The present invention related to a permanent magnetic work holder, or referred to hereinafter as a sucker, particularly a light-weight magnetic sucker with high strength and stability through application of fusion weld at high temperature for assembly of magnetic conductive disk and sucker in order to improve working efficiency and to prolong service life.
Conventionally permanent magnetic sucker is incorporated with a case iron base. Hence, it is quite heavy, working efficiency is limited, particularly where a large sucker is required. Prolonged use of such sucker would deteriorate machining precision. Moreover, the cam for its operating lever is made of steel which is designed to keep constant contact with the base. Such a design does not only make maintenance very difficult, and cause seizing of the operating lever at the base frequently. Seizing is always a trouble to its operator for its is very difficult to maintain the contact for it is inside the base. Furthermore, the sucker assembly of the prior art is formed by soldering, its bonding strength is weak, change of temperature can affect the levelness of the surface of the sucker, and consequently adversely affect the precision of machining.
In view of the above defects, the inventor has created a new structure of permanent magnetic sucker which makes use of aluminum alloy for making of the base to minimize its weight, two pads at the bottom of the base to facilitate use of large electromagnetic sucker, a copper alloy sleeve for the operating level to prevent from being seized, and fusion weld at high temperature for assembly of the magnetic conductive disk and sucker to eliminate impurities, to assure high bonding strength and stability for the highest possible machining precision.